docs: def _get_doubles_target(module, class_name, path):
      """Validate and return the class to be doubled.
  
      :param module module: The module that contains the class that will be doubled.
      :param str class_name: The name of the class that will be doubled.
      :param str path: The full path to the class that will be doubled.
      :return: The class that will be doubled.
      :rtype: type
      :raise: ``VerifyingDoubleImportError`` if the target object doesn't exist or isn't a class.
      """
  
      try:
          doubles_target = getattr(module, class_name)
          if isinstance(doubles_target, ObjectDouble):
              return doubles_target._doubles_target
  
          if not isclass(doubles_target):
              raise VerifyingDoubleImportError(
                  'Path does not point to a class: {}.'.format(path)
              )
  
          return doubles_target
      except AttributeError:
          raise VerifyingDoubleImportError(
              'No object at path: {}.'.format(path)
          )